qt@gentoo.org Gentoo Qt Project Build the extra compatibility layer required by a few packages, see http://blog.qt.io/blog/2010/06/22/qt-assistant-compat-version-available-as-extra-source-package/ Add support for exceptions - like catching them inside the event loop (recommended by upstream) https://bugreports.qt.io/ https://doc.qt.io/ Must only be used by packages that are known to use private parts of the Qt API.